Granulation of Fe-Al-Ce trimetal hydroxide as a fluoride adsorbent using the extrusion method

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• 作者：Bei Zhao^a ; Yu Zhang^a ; ^{zhangyu@rcees.ac.cn} ; Xiaomin Dou^b ; Xiaomei Wu^a ; ^c ; Min Yang^a
• 关键词：Fluoride removal ; Granulation ; Adsorption ; Adsorbent ; Groundwater
• 刊名：Chemical Engineering Journal
• 出版年：2012
• 期刊代码：16_13858947
• 类别：ce
• 出版时间：15 March, 2012
• 卷：185-186
• 期：Complete
• 页码：211-218
• 文件大小：1044 K

摘要

Iron-aluminum-cerium hydroxide (Fe-Al-Ce), which has high fluoride (F) adsorption capacity, was granulated via extrusion with cross-linked poly (vinyl alcohol) (PVA) as the binder. The optimum granulation conditions for acquiring an adsorbent with a high F adsorption capacity and compression strength were: binder/Fe-Al-Ce powder ratio, 1.4; average cylinder diameter of granules, 1.6 mm; and drying temperature, 65 掳C. The granulated Fe-Al-Ce (GFAC) exhibited a Langmuir maximum adsorption capacity of 51.3 mg g^鈭? at pH 7.0 卤 0.2. The GFAC in columns exhibited an accumulated F adsorption capacity of 5.7 mg g^鈭? and 3.2 mg g^鈭? at the breakthrough point (1.0 mg F l^鈭?) for treatment of F-spiked tap water (pH 7.8 卤 0.2) and F-bearing groundwater (pH 8.2 卤 0.2), respectively, which is several times higher than most reported F adsorbents under the same conditions. Energy dispersive X-ray micro analysis (EDX) showed that F was distributed evenly in the cross-section of the used GAFC, suggesting that most active sites inside the GFAC were available for F removal. A regeneration method using NaAlO₂ solution to desorb F from the used GFAC was developed, permitting the GFAC to keep over 60%of its F adsorption capacity even after four adsorption-regeneration cycles. The results demonstrated that GFAC was superior in F adsorption performance to conventional adsorbents such as activated alumina.